Perhaps you should try some spelling variations:
"thu hoc cong snippets" » "thu hoc code snippets", "thu hoc co snippets", "thu cac cong snippets", "thu hoc dung snippets", "tu hoc cong snippets", "thu hoi cong snippets", "tru hoc cong snippets"
"locating bug core snippets" » "locating bug code snippets"
"python using java snippets" » "python using data snippets"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("python using java snippets") or ("thu hoc cong snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("python using java snippets") OR ("thu hoc cong snippets"))) OR ("locating bug core snippets")).
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• Adding a wildcard symbol may retrieve word variants: (((("python using java snippets") or ("thu hoc cong snippets"))) or ("locating bug core snippets"))*.